Question

As you go above the earth's surface, the acceleration due to gravity will decrease. find the height, in meters, above the earth's surface where this value will be 1/140 g.

Answer 1

Gravitational force follows an inverse square law, so your distance will be
√140 ≈ 11.832160
times the radius of the earth from the center of the earth, or 10.832160 times the radius of the earth above the surface.

That distance is about (6.371·10^6 m)·10.832160 ≈ 6.901·10^7 m.